This study was performed to examine the in vitro toxicities which are incurred due to the mobilization metals from standard reference material (SRM) 1648, fine (), and coarse () particulate matter collected in Seoul metropolitan area. DNA single strand breaks of approximately 74% and 62% for and for , respectively, were observed in the presence of chelator (EDTA or citrate)/reductant (ascorbate), as compared to the control by 2% without chelator or reductant. induced about 40% more carbonyl formation with proteins in the presence of EDTA/ascorbate than . Therefore, more damage to biomolecules was incurred upon exposure to than to . The treatment of a specific chelator, desferrioxamine, to the reaction mixture containing chelator plus reductant decreased the extent of damage to DNA to the level of the control, but did not substantially decrease the extent of damage to proteins. This suggests that different arrays of metals were involved in the oxidation of DNA and proteins.